Gather data on recreational public spaces and extract features

[jasonasher]

The purpose of this issue is to collect data sets about recreational public spaces and extract features of interest (counting proximity to parks by count and size, e.g.). This issue also requires elaboration to make the final product more clear.

Some notes and initial data sets:

Research article showing association between recreational public space and rodent sightings: https://peerj.com/articles/533.pdf

Properties under the jurisdiction of the DC Department of Parks and Recreation (with possible other variables of interest like VSTRSHCAN and PICNIC): http://opendata.dc.gov/datasets/287eaa2ecbff4d699762bbc6795ffdca_9

Other datasets may be relevant as well.